Purification of human liver microsomal NADPH-cytochrome P-450 reductase to homogeneity. Purification of human liver microsomal epoxide hydratase to homogeneity. Purification of individual human liver microsomal cytochromes P-450 to homogeneity. Preparation of monospecific antibodies to each of the above purified proteins. Reconstitution of enzyme activity towards polycyclic hydrocarbons and other substrates. Physical characterization of purified human liver proteins for comparison to animal enzymes. Comparison of substrate specificities of purified human liver enzymes with those obtained from animals.